photoengraving vs photogravure

photoengraving

noun
  • A process of transferring a photographic image onto a plate which is then etched and printed. 

  • A plate or reproduction made using this process. 

photogravure

noun
  • An intaglio process for printing photographic reproductions in newspapers and books. 

  • A print so made. 

verb
  • To print by this process. 

How often have the words photoengraving and photogravure occurred in a corpus of books? (source: Google Ngram Viewer )